Videos on an over the top (OTT) video website are classified into video on demand (VOD) and video on live (VOL) according to watching forms.
Video on demand refers to: Watch videos stored on a video server. Because the videos have been produced completely, during watching, the videos may be stopped, fast-forwarded, or rewound at any time, or progress bars of the videos may be dragged forward or backward at any time.
Video on live refers to: Play a real-time video, which is generally content of various television channels, or outside broadcasting of sports events or concerts. In this case, a progress bar cannot be dragged forward or backward, and audiences watching same live media data watch totally same content.
An OTT server is owned by an OTT service provider (a company providing an OTT video website service), and may be placed in a data center of an operator in a particular city, or may be placed in a machine room of the OTT service provider. The OTT server can provide services of registration, login, presenting a program window, sending streaming media, or the like to an OTT user. During specific deployment of the OTT server, usually multiple physical servers provide a function to the outside together.
An OTT client refers to a terminal on which an OTT user watches an OTT video. Three common forms of the OTT client are: a desktop client on a desktop computer or a notebook computer, a mobile application on a mobile phone or a tablet computer, and an OTT set top box.
Currently, most of video transmission on an OTT video website is unicast based on the Hypertext Transfer Protocol (HTTP), and some video transmission is unicast based on the User Datagram Protocol (UDP). This means that an OTT user watching live media data transmits a large quantity of repeated data packets on a network. The large quantity of repeated packets of the live media data seriously occupies bandwidth of a bearer network.